172 
Psyche 
[October 
merella, Hexagenia, Potamanthus and Bactis. Two species have 
been described from adults. Ephemera exsucca Scudd. has an 
expanse of only 16 mm.; E. howarthi Ckll has three strong tails, 
as in true Ephemera. In the somewhat arched costa and broad 
costal area Siphlurites agrees with Cronicus anomalus (Pictet) 
from Baltic amber, but is is otherwise quite different. 
It is worthy of note that in the Permian Protereisma and 
Protechma of Sellards the first cubitus emits a couple of veins at 
very acute angles (not curved at base as the long branch of 
Siphlurites), and these proceed distad to the margin, subparallel 
with the first cubitus. Thus the special feature of Siphlurites 
may be regarded as primitive. The Permian insects constitute 
a distinct family Protereismatidse, having the lower wings almost 
or quite as large as the upper. 
